Actor and songwriter Alan Thicke, best known as Growing Pains dad Jason Seaver, has passed away. Deadline reports that Thicke passed after suffering a heart attack late this afternoon. He was 69.

Thicke had a long, prolific career in film and television that spanned over four decades of work. He was most well known as sitcom dad Jason Seaver on ABC’s Growing Pains, but he also made a big name for himself with his theme songs. Thicke, a talented songwriter, composed the themes to such classic shows as Diff’rent Strokes and The Facts of Life.

Thicke has been appearing on television since the late 60s/early 70s, working as a game and talk show host as well as a producer and writer. He eventually produced and worked as head writer for Norman Lear on Fernwood 2 Night before going on to host his own series including The Alan Thicke Show and Thicke of the Night. After Growing Pains Thicke kept on working, consistently appearing on major TV shows for the next twenty years like Hope & Gloria, Married with Children, 7th Heaven, Tim and Eric Awesome Show, Great Job!, The Bold and the Beautiful, How I Met Your Mother, American Dad!, Scream Queens, Mike Tyson Mysteries, This Is Us, and was most recently on Fuller House.

So sad is the passing of Alan Thicke. Such a good husband, father, brother, and friend. He will be deeply missed. Rest in peace dear Alan.

— bob saget (@bobsaget) December 14, 2016

RIP Alan Thicke. We skated side by side for years. Say hello to Gordie and The Rocket for me. Our Canadian Mounties sketch @jimmykimmel pic.twitter.com/YE5SiFRtsf

— Dave Coulier (@DaveCoulier) December 14, 2016

America loved Alan Thicke. I'm so sad he's gone. Sending so much love to his family.

— Ellen DeGeneres (@TheEllenShow) December 14, 2016

Saddened over the loss of my friend Alan. Condolences to his family.

— William Shatner (@WilliamShatner) December 14, 2016

sad to learn of Alan Thicke's passing. he was a great friend over the years. thoughts & prayers to his family.

— Ryan Seacrest (@RyanSeacrest) December 14, 2016